Physics - EMI/AC Question with Solution | TestHub
A bar magnet is moved along the axis of copper ring placed far away from the magnet. Looking from the side of the magnet, an anticlockwise current is found to be induced in the ring. Which of the following may be true?
Options:(select one or more)
Answer:
Solution:
An anticlockwise induced current as seen from the magnet side means the induced field points out of the ring face towards the magnet.
By Lenz law, this happens when the flux pointing away from the magnet increases, or the flux pointing towards the magnet decreases.
(B) North pole facing the ring and approaching: flux directed away from the magnet increases → induced field towards the magnet → anticlockwise current. Correct.
(C) South pole facing the ring and receding: flux directed towards the magnet decreases → induced field towards the magnet → anticlockwise current. Correct.
(A) and (D) give the opposite (clockwise) current.
Hence (B) and (C).
